Risks and benefits of long-term hormone replacement therapy.

Studies of long-term hormone replacement therapy (HRT) are reviewed, and treatment recommendations based on the results are advanced. HRT is a popular therapy for postmenopausal symptoms and osteoporosis prevention in women. However, women also use hormones for unlabeled indications, such as cardiovascular disease prevention. In the past, observational and case-controlled trials have suggested that HRT confers a benefit through an improvement in lipid profiles and has relatively few adverse effects. However, no randomized controlled trial had proven this before HRT became popular. More recently, the results of additional observational studies and large, double-blind, placebo-controlled trials have been published that indicate that HRT may not be as beneficial or risk free as first thought. If a woman wishes to begin or continue HRT for short-term menopausal symptoms, it is crucial to evaluate her individual risk of breast cancer, coronary heart disease, venous thromboembolism, and stroke before recommending therapy. Otherwise, HRT should not be recommended for treatment durations of more than five years, and treatment should be discontinued in women at risk of complications. Recent large, randomized, placebo-controlled trials have shown substantial risks and limited benefits in the long-term use of HRT.